Manufacturing tea.

Once the tender leaves have been plucked from the tea bush, they can be made into black tea, Oolong or red tea, or green tea. These types of tea result primarily from differences in the process of oxidation.

There are two methods of manufacturing tea - 'orthodox' used to make loose teas and 'CTC' or 'Cut, Tear & Curl' used to make bag teas. At Twinings, the quality of the tea is the same whether in loose or tea bag format. In fact, our Lady Grey teabags are renowned for the fact that experts can't taste the difference between them and the loose tea blend. Read more about tea manufacturing here.

Orthodox

In the traditional, or 'orthodox' procedure, the process used to make loose tea, the leaves must go through a process of Withering, Rolling, Oxidation and Drying.

Withering

The objective of withering is to reduce the moisture in the tea leaf by up to 70%, depending on the region in which it's been grown. The tea leaves are laid out on a wire mesh in troughs. Air is then passed through these troughs so that the moisture is removed in a uniform way. This process takes between 12 and 17 hours, until the leaves are limp and pliable and will roll well.

Rolling

The tea leaves are then placed into a rolling machine, which rotates horizontally on a rolling table. This action creates the twisted wiry looking tea leaves. During the rolling process the leaves are also broken open, which starts the third process - oxidisation.

Oxidation

Oxidation, otherwise known as fermentation, is an extremely important part of tea production. The process of oxidisation ultimately creates the different types of tea - black, oolong and green. These teas differ in the amount, or lack of, oxidisation. Black teas are fully oxidised. Oolong teas are partially oxidised. Green teas are not oxidized.

It's oxidation that contributes the most to a tea's flavour, colour and strength. This stage is critical to the final flavour of the tea. If left too long, the flavour will be spoilt. To oxidise tea, the leaves are put into troughs or laid out on tables. Oxidisation occurs when enzymes within the leaves react with the air and takes from between 30 minutes and two hours at about 26 degrees centigrade. It is during this process that the tea leaf changes from green, through light brown to a deep brown. Once the tea has reached the desired level of oxidation, light for a light liquoring tea and dark brown for a stronger liquoring tea, the leaves are dried (otherwise known as 'firing the tea').

Drying

To stop the oxidisation process, the tea is passed through hot air dryers. This reduces the total moisture content down to about 3% and the dried tea is ready to be sorted into grades before packing.

CTC - Cut, Tear & Curl

The 'CTC', or 'Cut, Tear and Curl' method was invented during World War II to increase the weight of the tea that can be packed into a sack or chest. The 'CTC' process follows that of orthodox manufacture up to the rolling stage. Instead of rolling the leaves, the 'CTC' technique passes the leaves through a series of cylindrical rollers with hundreds of small sharp "teeth" that Cut, Tear, and Curl. This creates a smaller granular type leaf, ideal for brewing from teabags. 'CTC' does not alter in any way the quality of the tea leaves. Following this stage, leaves follow the same processes of oxidation and drying as described earlier in this section.

Making different types of tea.

Although most tea comes from the same plant, the process by which it is produced varies.

Black tea

Black teas are the world's most commonly produced tea. Like red wine, black teas are fuller bodied and have stronger flavours. The stronger flavours and deeper colours are a result of oxidation. Of the three major tea types (black, oolong, and green), black teas are fully oxidized, undergoing the longest process of oxidation.

Oolong tea

Oolong teas follow the same path as black teas, except that they are only oxidised for a very short period of time, creating the distinctive coppery edged leaf colour and a delicate flavour. Oolong tea traditionally comes from two small tea growing areas, Fujian, a south east province of China, and Taiwan, where it is known as Formosa Oolong.

Green tea

When making green tea, the oxidisation process is omitted, which allows the tea to remain green in colour and keep its very delicate flavour. In order to ensure that the freshly picked leaf does not oxidise, the leaves are either pan fried or steamed to kill active enzymes in the leaf before rolling. This prevents the air from interacting with any of the enzymes in the leaf, so no oxidisation takes place. In China, some green teas are withered before being pan dried, but more commonly the withering process is omitted and the teas go straight to the rolling process.

Decaffeinated teas

Twinings decaffeinated teas are decaffeinated using carbon dioxide under super critical conditions. Carbon dioxide is a natural substance in the very air we breathe and leaves no residues in the decaffeinated tea. Carbon dioxide is generally recognised as safe (GRAS) and is widely used within the food industry - it is the "fizz" in carbonated beverages, and the gas that causes bread to rise.

Herbal tea

Although often referred to as "herbal tea", fruit and herbal infusions do not come from the Camelia Sinensis plant, thus they do not contain tea. Herbals are made from other plants, such as mint, lemon, and camomile. Naturally caffeine-free and low in calories, they are popular for their calming and medicinal-like qualities.